Method of making composite metallic elements



March 28, 1939.- CE SWARTZ v 2,152,611

METHOD OF MAKING COMPOSITE METALLIC ELEMENTS Filed July 22, 1936INVENTOR- 1 BY Car/ cf 521M227? ATTORN 5.

. results due the materials into a Patented an 2, i$3

Carl E. Swartz,

pany, Gleveland, Application .iuly 22, 2 Claims.

trolled frictional properties; and wherein a strong and adequate bondwill be provided between the composite layers.

It is old in the. art to produce a composite material by mixing togetherfinely divided copper, lead, tin, graphite and, in some material, applya heavy pressure to a selected portion of such a mixture and at the sametime subject the mixture to heat sufficient to sinter' solid integralmass. Such composite articles as made in the past, however, have beensomewhat brittle and have been difficult to bond or unite to asupporting member to supply the strength which is lacking in thecomposite article itself. Where such articles have been unitedtosupporting members, such as steel plates or the like, the operationhas been lengthy and expensive, involving successive, intermittent stepsof operation, and has not always given uniform. or satisfactory results.

In the method embodying the principle of my invention, however, tivecosts, and satisfactory results heretofore inherent in prior artpractices are obviated. In the present method the loose, unpressedmetallic powder mixture is transformed directly into a sintered materialbonded to the solid metal body of the supporting layer in a singleoperation. That is to say, the steps of forming, sintering and bondingof the metallic powdered mixture to the solid metal supporting elementare accomplished in my method in a single operation, and not insuccessive step by step operations heretofore taught by the art.

My novel method possesses the advantages in that (1) it is capable ofmore rapid operation and hence adaptable to quantity and practicalcommercial production, (2) the operating pressures are greatly reduced,(3) better un'formity and density of the sintered material is obtained,(4) improved grain structure of the sintered material to the aiding andencouraging of grain growth between simultaneous application of pressureand heat,

instances, inert the disadvantages, prohibithe metallic particles duringthe oosrrs are Cleveland Heights, Ohio, assignor to The ClevelandGraphite Bronze Ohio, a corporation of Ohio H36, Serial No. 91,869

Com-

and (5) the elimination of excessive oxidation resulting in improvedphysical properties of the sintered metallic material and a strong andsatisfactory bcnd between the composite layers.

To the accomplishment of the related ends, my invention, then, consistsof the steps hereinafter fully described and particularly pointed out inthe claims; the following descrip tion setting forth in detail certainsteps embody ing the invention, such disclosed steps ing, however, butone of .the various ways in which the principle of the invention may-beused.

In the annexed drawing:

Fig. l is a perspective view of a ring of the solid supporting metalelement, such is a sectional view of the ring of Fig. 1 showing a layerof protective material applied thereto precedent to its use in theperformance of my process; Figs. 3 and 4 are sectional viewsillustrating an apparatus applicable to perform the procgo the principleof my invention, the parts thereof being shown in different positions ofoperation; and Fig. 5 is a sectional view of the finished product.

ess embodying The herein described and claimed method is 25 form of aflat rin In the practice of my process, the supporting 5 layer orelement l is placed in a die cavity 3. The steel ring I has amechanically and chemically cleaned surface produced by abrading,polishing, machining, sand blasting, or pickling, which cleaned surfaceoxidation or contamination by a non-reactive coating 4 either consistingof a high flash point oil or of a thin flash coatingof copper plate.Heating means is provided in the wall surroundmg conductors 5 adapted toproduce heat in the interio'r of the die cavity either throughelectricalinduction or resistance methods. The die cavity 3 issurrounded by an insulating housing 6 which has an opening 1 plunger 8.The plunger 8 has a central recess 9 adapted to accommodate the centralprojection Ni from the die cavity 3.

After the steel ring I is placed in the die cavity 3, a quantity ofmetallic powdered material It is foregoing and 5 constitut- 10 as steel;Fig. 2 l5 practice of my method is a of the reinforcing and supportingis protected against subsequent m the die cavity 3 and may consist ofelectric therein for the passage of a to the materials,

stituent of such powdered be a non-ferrous metal.

strength and density.

After the powdered mixture I has been pressed, sintered and bonded tothe steel ring I, the plungby way of example, may be between 1450"and1950 F. in the case of a copper base powdered mixture.

Relatively low presinto a hot mold and rapidly brought to sintering andbonding temperature.

Other modes of applying the principle of my I therefore particularlypoint out and distinctly claim as my invention:- 1. In a method ofelements,

to 2000 pounds per square inch, forming and heating to a temperature of1450 to -1950 F. a copper base powdered material while in contact withthe element, steps being performed simultaneously.

2. In a method 'of making composite metallic elements, the steps ofproviding a steel supporting pounds per square inch, forming and heatingto a temperature of 1450 to 1950 F. a powdered metal CARL E. SWARTZ.

